1. Field of the Invention
The present invention relates to a contact pad array, and more particularly, to a contact pad array with high space utilization efficiency, in which projections of contact pads disposed in the same column overlap with each other on the column direction.
2. Description of the Prior Art
Due to popularity of multi-media applications, display screens with small sizes can no longer satisfy public requirements, so that manufacturers are devoted to developing larger and thinner display panels. Thus, the number of pixels of the display panels should be increased to maintain display resolutions and to provide exquisite images. Therefore, the number of input terminals of scan lines and data lines should be increased when designing the display panels with large sizes.
For example, in a QVGA (quarter Video Graphics Array) display with a resolution of 320×240, 960 output terminals (320×3(RGB)) are required for data lines, and 240 output terminals are required for scan lines, thus, at least 1200 output terminals are required; in a VGA display with a resolution of 640×480, at least 2400 (640×3+480) output terminals are required; and also, in a UXGA display with a resolution of 1600×1200, at least 6000 (1600×3+1200) output terminals are required. Therefore, to maintain high display resolutions of the display panels with large sizes, the number of output terminals should be also increased to provide a signal for each data line or each scan line. Generally, the output signals are provided by driver chips. Please refer to FIG. 1, which schematically illustrates configurations of a conventional display panel and a driver chip. As shown in FIG. 1, a contact pad array 102 is disposed on the display panel 100. The contact pad array 102 includes a plurality of contact pads 104, and each contact pad 104 is correspondingly connected to a wire 106. Also, a contact pad array 110 is disposed on the driver chip 108, and the contact pad array 110 includes a plurality of contact pads 112. Additionally, an arrangement of the contact pad array 110 disposed on the driver chip 108 corresponds to the contact pad array 102 disposed on the display panel 100 under the driver chip 108. As a result, after installing the driver chip 108 to the display panel 100, signals generated by the driver chip 108 can be transmitted the to the contact pad array 102 disposed on the display panel 100 via the contact pad array 110, and then the signals are respectively transmitted to data lines (not shown) and scan lines (not shown) disposed on the display panel 100 by the wires 106 for the sake of driving display devices (not shown) disposed on the display panel 100.
As previously described, the display panels with large sizes and high display resolutions require more contact pads, and therefore the arrangements of the conventional contact pad arrays 102, 110 are no longer favorable for present requirements. Please refer to FIG. 2, which schematically illustrates an arrangement of the conventional contact pad array. As shown in FIG. 2, in order to ensure the wires 106 are connected to each contact pad 104, respectively, the contact pads 104 of the contact pad array 102 are usually disposed with a staggered arrangement. In other words, any two of the adjacent contact pads, such as 104a and 104b, do not horizontally overlap with each other, so that the wires 106 can be perpendicularly extended without electrical connections between each other. Wherein a projection area of each contact pad is the same. In accordance with FIG. 2, however, the staggered arrangement is disadvantageous for space utilization, since a portion of space is not used. For this reason, when the number of the contact pads 104 is increased, the areas of the contact pad arrays 102,110 with the conventional arrangement will be highly magnified and therefore unfavorable for product designing.